Device and method for safe access and automated therapy

ABSTRACT

An automated therapy system having an infusion catheter; a sensor adapted to sense a patient parameter; and a controller communicating with the sensor and programmed to control flow output from the infusion catheter into a patient based on the patient parameter without removing fluid from the patient. The invention also includes a method of controlling infusion of a fluid to a patient. The method includes the following steps: monitoring a patient parameter with a sensor to generate a sensor signal; providing the sensor signal to a controller; and adjusting fluid flow to the patient based on the sensor signal without removing fluid from the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/993,483 filed May 30, 2018, which is a continuation of U.S.application Ser. No. 15/013,813 filed Feb. 2, 2016, which is acontinuation of U.S. application Ser. No. 13/937,102 filed Jul. 8, 2013(now abandoned), which is a continuation of U.S. application Ser. No.13/354,210 filed Jan. 19, 2012 (now U.S. Pat. No. 8,480,648), which is acontinuation of U.S. application Ser. No. 12/098,365 filed Apr. 4, 2008(now U.S. Pat. No. 8,100,880), which claims the benefit of U.S.Provisional Application No. 60/921,974 filed Apr. 5, 2007 to Burnett,entitled “Safety Access Device, Fluid Output Monitor & Peritoneal OrganPreservation”, all disclosures of which are incorporated by referenceherein in their entirety.

FIELD OF THE INVENTION

The present invention relates to the field of medical devices, inparticular devices capable safely accessing bodily spaces or cavities.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND OF THE INVENTION

Fluids and other substances are infused into patients for a variety ofreasons. For example, fluids may be given to a patient intravenously tohydrate the patient or to control overall blood volume.

It is often important to control infusion of fluid into patients inorder to optimize the therapy being provided. Monitoring of patientparameters can consume precious health care time and resources, however.Fluid infusion into patients is therefore not always optimized.

Mantle US 2006/0161107 describes a system that extracts fluid from abody cavity, processes the fluid and then recirculates fluid back intothe cavity. Mantle does not describe infusion of a fluid into a patientwithout extraction of the fluid from the patient, however. In addition,the parameters on which the Mantle system is controlled are limited.

SUMMARY OF THE INVENTION

One aspect of the invention provides an automated therapy system havingan infusion catheter; a sensor adapted to sense a patient parameter; anda controller communicating with the sensor and programmed to controlflow output from the infusion catheter into a patient based on thepatient parameter without removing fluid from the patient. In someembodiments, the sensor may be incorporated into the catheter, and inother embodiments, the sensor may be separate from the catheter. Thesensor may be, e.g., an ECG sensor; an EEG sensor; a pulse oximetrysensor; a blood pressure sensor; a cardiac output sensor; athermodilution cardiac output sensor; a cardiac stroke volume sensor; aheart rate sensor; a blood flow sensor; a pH sensor; a blood pO₂ sensor;an intracranial pressure sensor; and/or a solute sensor.

In embodiments of the invention, the catheter may be a peripheral venouscatheter; a central venous catheter; an arterial catheter; or aperitoneal catheter (possibly incorporating an intraperitoneal pressuresensor).

Another aspect of the invention provides a method of controllinginfusion of a fluid to a patient. The method includes the followingsteps: monitoring a patient parameter with a sensor to generate a sensorsignal; providing the sensor signal to a controller; and adjusting fluidflow to the patient based on the sensor signal without removing fluidfrom the patient. In some embodiments, the method includes the step ofmonitoring cardiac output with the sensor and, possibly, adjusting fluidflow to the patient based on cardiac output monitored by the sensor. Inembodiments of the invention, the patient parameter includes anelectrocardiogram; an electroencephalogram; blood oxygen saturation;blood pressure; cardiac output; cardiac stroke volume; heart rate; bloodflow; total circulating blood volume; whole body oxygen consumption; pH;blood pO₂; osmolarity; peritoneal cavity compliance; intrathoracicpressure; bladder pressure; and/or rectal pressure.

In some embodiments, the adjusting step includes the step of adjustingfluid flow to achieve or maintain patient euvolumia; adjusting flow of atherapeutic agent (such as a chilled medium) to the patient; adjustingfluid flow to the patient through a peripheral venous catheter;adjusting fluid flow to the patient through a central venous catheter;adjusting fluid flow to the patient through an arterial catheter; and/oradjusting fluid flow to the patient's peritoneal cavity.

Yet another aspect of the invention provides a method of treatinghypotension in a patient. The method includes the following steps:monitoring a patient parameter (such as blood pressure or cardiacoutput) with a sensor to generate a sensor signal; providing the sensorsignal to a controller; and adjusting fluid flow to the patient based onthe sensor signal without removing fluid from the patient.

Still another aspect of the invention provides a method of treatingsepsis in a patient. The method includes the following steps: monitoringa patient parameter (such as blood pressure, central venous pressure, orcardiac output) with a sensor to generate a sensor signal; providing thesensor signal to a controller; and adjusting fluid flow to the patientbased on the sensor signal without removing fluid from the patient.Prevention of hypotension and/or hypovolemia is critical in the care ofpatients that have suffered severe hemorrhage or are septic. Thesepatients are very difficult to monitor and treat, taking significantnursing time and still resulting in suboptimal therapy due to theintermittent nature of the blood pressure, central venous pressureand/or cardiac output checks. The present invention, then, will optimizefluid flow to the patient while also freeing up the already over-taxednursing staff for other duties.

Yet another aspect of the invention provides a method of inducing andreversing therapeutic hypothermia in a patient. The method includes thesteps of: monitoring intracranial pressure to generate a sensor signal;providing the sensor signal to a controller; and adjusting rate ofhypothermia induction or rewarming based on intracranial pressure (suchas by adjusting fluid flow to the patient), or depth of hypothermia,based on the sensor signal.

In some embodiments of the invention, irrigation and/or lavage of bodilytissues, cavities or spaces (or other patient interventions) may beoptimized using a sensor or sensors to report electrical, chemical,acoustic, mechanical properties, pressure, temperature, pH or otherparameters surrounding the access device in order to automate andoptimize the irrigation/lavage.

Embodiments of the invention include a peritoneal catheter containingone or more sensors which may detect changes in electrocardiographmonitoring, electroencephalograph monitoring, pulse oximetry (eitherinternally or peripherally), peritoneal cavity compliance, intrathoracicpressure, intraperitoneal pressure, intraperitoneal pressure waveforms,bladder pressure, rectal pressure, cardiac output, cardiac strokevolume, cardiac rate, blood flow (e.g., in superior mesenteric, celiac,renal or other arteries), pressure in veins (particularly the inferiorvena cava or those that empty into the inferior vena cava, e.g., femoralvein), pressure in arteries (particularly those distal to the aorta,e.g., the femoral artery), total circulating blood volume, bloodoxygenation (e.g., in rectal mucosa, peripheral fingers and toes, etc.),whole body oxygen consumption, pH and/or arterial pO₂ (or any otherparameter that shows a measurable change with increased peritonealpressure) to ensure safety of automated or manual peritoneal lavage. Theinvention also includes methods of performing peritoneal lavage usingsuch devices.

Embodiments of the invention include an intravascular cathetercontaining one or more sensors which may detect changes inelectrocardiograph monitoring, electroencephalograph monitoring, pulseoximetry (either internally or peripherally), partial pressure of oxygenor CO₂, pH, temperature, blood pressure, central venous pressure,cardiac output, cardiac stroke volume, cardiac rate, blood flow (e.g.,in superior mesenteric, celiac, renal or other arteries), totalcirculating blood volume, pressure in veins (particularly those thatempty into the inferior vena cava, e.g., femoral vein), pressure inarteries (particularly those distal to the aorta, e.g., the femoralartery), blood oxygenation (e.g., in rectal mucosa, peripheral fingersand toes, etc.), whole body oxygen consumption, pH and/or arterial pO₂(or any other parameter that shows a measurable change withintravascular volume overload) to ensure safety of manual or automatedintravascular infusion. The invention also includes methods of usingsuch devices.

Other embodiments of the invention include control of the rate ofinfusion to minimize negative effects observed by the sensors. Theinvention may be used to induce and/or maintain hypothermia orhyperthermia; maximize hydration and/or intravascular volume in apatient receiving intravenous fluids (such as, e.g., post-operativepatients, post-hemorrhage patients, septic patients or other intensivecare patients).

Disclosed is a method and device for detection of intake and/or outputin an individual. Fluid detection may be fully automated and the usermay be alerted if volumes become too low or too high. The data may alsobe automatically routed to a centralized data collection server so thatit may be collected and accessed without the requirement for nursing orother healthcare personnel to record the information manually. Theoutput receptacle, in particular, may contain wireless technology, ieRFID, as well to optimize data collection and reduce nursing burden.

In reviewing the obstacles of urine output monitoring and datacollection, then, it becomes clear that what is needed for widespreadadoption is an easily implemented system capable of accurately measuringurine output wherein the use of the device reduces the nursing burdenwhile reporting any issues with urine output in a timely manner. Thepresent invention may also measure and report bladder temperature inreal-time and this information may be used to alert the healthcareproviders of changes in therapy and/or may be used to control and directdepth of therapeutic hypothermia. The reservoir/receptacle may alsocontain sensors capable of detecting other materials of interest withinthe fluid including, but not limited to: hemoglobin, blood, bacteria,leukocyte esterase, glucose, protein, particulate matter, etc. Thisinformation may also trigger an alert to provide real-time datamonitoring of these parameters. Additionally, the present inventionanticipates the use of wired or, ideally, wireless transmission of datato allow for centralized collection of data and centralized reporting.This is, once again, useful in reducing healthcare provider burden byallowing fewer personnel to monitor the data from all of the patientsutilizing said system.

In addition, the system of the present invention anticipates the use ofRFID technology within or attached to the reservoir itself which may beremotely queried and interrogated by one or more RFID readers. The datacollected may be encrypted and specific to each receptacle such that theup.ne output reported may be securely associated with an individualpatient. In its optimal embodiment, the reservoir may contain conductingchannels connected to the RFID circuitry which determine the urine levelby detection of the level of a simple short-circuit through theconducting fluid itself which may then be reported by the RFID chip tothe reader. This cheap, easy-to-use system overcomes the obstacles ofprevious attempts to automate urine output monitoring.

In addition, information collected using the present invention may beused to automatically adjust therapeutic hypothermia, delivery ofmedicine or other interventions.

Disclosed is a method and device for safe access of a bodily tissues,spaces or cavities and automated therapy. The improved safety of thecurrent invention is based, in part, on the ability of the access systemto report entrance into the tissue/space/cavity via an integratedsensor. In its preferred embodiment, additional sensing capabilities maybe incorporated, as well, to optimize the automated therapy delivered orintervention required.

In reviewing the obstacles of providing safe access to bodily cavitiesand spaces, it becomes clear that over- and under-insertion of invasiveinstrumentation is a major issue. During catheter placement in majorvessels, for example, many of the complications that occur are due toover-insertion of the insertion needle or sliding of the catheter overthe needle at a point when the needle is not appropriately positioned.The disclosed invention, then, is a method and device for safe access ofa bodily tissues, spaces or cavities. The improved safety of the currentinvention is based, in part, on the ability of the access system toreport entrance into the tissue, space, or cavity via a sensorintegrated within, or inserted simultaneously with, the instrumentitself. In its preferred embodiment, additional sensing capabilities maybe incorporated, as well, to optimize the desired intervention ortherapy to be delivered.

1) A device for accessing bodily tissues, spaces or cavities outside ofthe respiratory tree wherein; said access device or its insertioninstrumentation incorporates a sensor and wherein said sensor may reportaccess to the desired tissues, spaces or cavities

2) The device of 1 wherein said sensor is capable of sensing optical,electrical, chemical, acoustic and/or mechanical properties todifferentiate between tissues, spaces or cavities and indicate when saiddevice is in the desired location

3) The device of 1 wherein said access device may incorporate additionalsensors in order to optimize therapy provided by said device

4) The device of 2 wherein said access device sensor may report entranceinto a cavity and wherein said additional sensor (or sensors) may reportpressure, temperature, pH or other parameters in order to optimizetherapy

5) The device of 2 wherein said cavity to be accessed may be theperitoneal cavity, and wherein said sensor may directly or indirectlydetect entry into this cavity.

6) The device of 4 wherein said additional sensors may directly orindirectly detect mechanical properties (such as pressure), chemicalcomposition, thermal properties, electrical properties, acousticproperties or optical ⋅ properties to optimize filling of the peritonealcavity with gases, liquids and/or solids.

7) The device of 2 wherein said cavity to be accessed may includeperitoneal, pleural, cerebrospinal, biliary, gastrointestinal, gastric,intestinal, urinary cavities, or pathologic tissues, and wherein saidsensor may directly or indirectly detect entry into this cavity.

8) The device of 2 wherein said space to be accessed may include thecardiovascular, venous, arterial, lymphatic, ureteral cerebrospinalventricular spaces, or pathologic spaces and wherein said sensor maydirectly or indirectly detect entry into this space.

9) The device of 2 wherein said tissues to be accessed may include lung,liver, heart, bladder, brain, intestinal, pancreatic, splenic, vasculartissues, or pathologic spaces and wherein said sensor may directly orindirectly detect entry into these tissues.

10) The device of 1 wherein said sensor is incorporated into the deviceitself.

11) The device of 1 wherein said sensor is incorporated into theinstrumentation required to insert said access device.

12) The device of 1 wherein said sensor may be introduced along withsaid access device and may be reversibly attached or contained withinsaid device.

13) The device of 1 wherein said sensor may be physically connected toan external display.

14) The device of 1 wherein said sensor may be wirelessly connected toan external display.

15) The device of 13 wherein said display may be incorporated into saidaccess device

16) The device of 13 wherein said display may be reversibly orirreversibly attached to an external display

17) The device of 14 wherein said display may be incorporated into saidaccess device

18) The device of 1 wherein said sensor may be intermittently activatedto detect the tissues surrounding the sensor

19) The device of 18 wherein said sensor may be repeatedly activated todetect the tissues surrounding the sensor

20) The device of 1 wherein said sensor continuously detects whichtissues surround the sensor

21) The device of 2 wherein said sensor detects optical transfer ofwavelengths from a transmitter to a, receiver and wherein the wavelengthconduction path includes the sensor incorporated within said device

22) The device of 2 wherein said sensor detects electrical propertiessurrounding said sensor to detect unique electrical signatures of thesurrounding tissues

23) The device of 2 wherein said sensor detects chemical properties (iealbumin, pH, etc.) surrounding said sensor to detect unique chemicalcomponents, or concentrations of components, within the tissues/spaces

24) The device of 2 wherein said sensor detects acoustic properties ofthe surrounding tissues/spaces to detect entrance into the desiredtissue/space

25) The device of 2 wherein said sensor detects mechanical properties(such as pressure, shear forces, etc.) surrounding said sensor to detectentrance into desired tissue/space

26) The device of 2 wherein multiple sensors of any type are used toindicate exact positioning and the composition of the fluid surroundingsaid device

27) The device of 26 wherein one or more sensors positively predicttissue/space access while one or more sensors negatively predicttissue/space access

28) The device of 26 wherein one or more sensors positively predicttissue/space access while one or more sensors detect potentialcomplicating factors, ie the presence of unexpected blood, etc.

29) The device of 3 wherein irrigation and/or lavage of bodily tissues,cavities or spaces is optimized by said additional sensors and whereinsaid access device contains a sensor to detect pressure, temperature, orother parameters to optimize the irrigation/lavage.

30) A method for accessing bodily tissues, spaces or cavities wherein;an access device or its insertion instrumentation incorporates a sensorand wherein said sensor may report access to the desired tissues, spacesor cavities

31) The method of 30 wherein said sensor is capable of sensing optical,electrical, chemical, acoustic and/or mechanical properties todifferentiate between tissues, spaces or cavities and indicate when saiddevice is in the desired location

32) The method of 30 wherein said access device may incorporateadditional sensors in order to optimize therapy provided by said device

33) The method of 31 wherein said access device sensor may reportentrance into a cavity and wherein said additional sensor (or sensors)may report electrical, chemical, acoustic, mechanical properties,pressure, temperature, pH or other parameters in order to optimizetherapy

34) The method of 31 wherein said cavity to be accessed may be theperitoneal cavity, and wherein said sensor may directly or indirectlydetect entry into this cavity

35) The method of 33 wherein said additional sensors may directly orindirectly detect mechanical properties (such as pressure), chemicalcomposition, electrical properties, acoustic properties or opticalproperties to optimize filling of the peritoneal cavity with gases,liquids and/or solids.

36) The method of 31 wherein said cavity to be accessed may includeperitoneal, pleural, cerebrospinal, biliary, gastrointestinal, gastric,intestinal, urinary cavities, or pathologic spaces and wherein saidsensor may directly or indirectly detect entry into one or more of thesecavities.

37) The method of 31 wherein said space to be accessed may include thecardiovascular, venous, arterial, lymphatic, ureteral cerebrospinalventricular spaces, or pathologic spaces and wherein said sensor maydirectly or indirectly detect entry into one or more of these spaces.

38) The method of 31 wherein said tissues to be accessed may includelung, liver, heart, bladder, brain, intestinal, pancreatic, splenic,vascular tissues, or pathologic spaces and wherein said sensor maydirectly or indirectly detect entry into one or more of these tissues.

39) The method of 30 wherein said sensor is incorporated into the deviceitself.

40) The method of 30 wherein said sensor is incorporated into theinstrumentation required to insert said access device.

41) The method of 30 wherein said sensor may be introduced along withsaid access device and may be reversibly attached or contained withinsaid device.

42) The method of 30 wherein said sensor may be physically connected toan external display.

43) The method of 30 wherein said sensor may be wirelessly connected toan external display.

44) The method of 42 wherein said display may be incorporated into saidaccess device

45) The method of 42 wherein said display may be reversibly orirreversibly attached to an external display

46) The method of 43 wherein said display may be incorporated into saidaccess device

47) The method of 30 wherein said sensor may be intermittently activatedto detect the tissues surrounding the sensor

48) The method of 47 wherein said sensor may be repeatedly activated todetect the tissues surrounding the sensor

49) The method of 30 wherein said sensor continuously detects whichtissues surround the sensor

50) The method of 31 wherein said sensor may detect optical transfer ofwavelengths from a transmitter to a receiver and wherein the location ofsaid device may be determined based on absorption or transmission ofsaid wavelengths

51) The method of 31 wherein said sensor detects electrical propertiessurrounding said sensor to detect and report unique electricalsignatures of the surrounding tissues and allow for avoidance ofundesirable tissues/spaces including conductance, impedance, resistance,capacitance, etc.

52) The method of 31 wherein said sensor detects chemical properties (iealbumin, pH, etc.) surrounding said sensor to detect unique chemicalcomponents, or concentrations of components, within the tissues/spacesand avoidance of undesirable tissues/spaces

53) The method of 31 wherein said sensor detects acoustic properties ofthe surrounding tissues/spaces to detect entrance into the desiredtissue/space and/or avoidance of undesirable tissues/spaces

54) The method of 31 wherein said sensor detects mechanical properties(such as pressure, shear forces, etc.) surrounding said sensor to detectentrance into desired tissue/space and/or avoidance of undesirabletissues/spaces

55) The method of 31 wherein said sensor detects thermal properties ofthe surrounding tissues/spaces to detect entrance into the desiredtissue/space and/or avoidance of undesirable tissues/spaces

55) The method of 31 wherein multiple sensors of any type may be used toindicate exact positioning and the composition of the fluid surroundingsaid device

56) The method of 55 wherein one or more sensors may be used topositively predict tissue/space access while one or more sensorsnegatively predict tissue/space access

57) The method of 55 wherein one or more sensors may be used topositively predict tissue/space access while one or more sensors detectpotential complicating factors, ie the presence of unexpected blood,etc.

58) The method of 55 Wherein one or more sensors may be used to providemultiple data points to help determine the exact position of said sensoror sensors.

59) The method of 32 wherein irrigation and/or lavage of bodily tissues,cavities or spaces may be optimized by said additional sensors andwherein said access device contains a sensor or sensors to reportelectrical, chemical, acoustic, mechanical properties, pressure,temperature, pH or other parameters surrounding the access device inorder to optimize said irrigation/lavage.

59) The method of 32 wherein an intervention performed in said tissues,cavities or spaces may be optimized by said additional sensors andwherein said access device contains a sensor or sensors to reportelectrical, chemical, acoustic, mechanical properties, pressure,temperature, pH or other parameters surrounding the access device inorder to optimize said intervention.

60) A peritoneal catheter containing one or more sensors which maydetect changes in electrocardiograph monitoring, electroencephalographmonitoring, pulse oximetry (either internally or peripherally),peritoneal cavity compliance, intrathoracic pressure, intraperitonealpressure, bladder pressure, rectal pressure, cardiac output, cardiacstroke volume, cardiac rate, blood flow (i.e. in superior mesenteric,celiac, renal or either arteries), pressure in veins (particularly thosethat empty into the IVC, i.e. femoral vein), pressure in arteries(particularly those distal to the aorta, i.e. the femoral artery), bloodoxygenation (i.e. in rectal mucosa, peripheral fingers and toes, etc.),whole body oxygen consumption, pH and/or arterial p02 (or any otherparameter that shows a measurable change with increased peritonealpressure) to ensure safety of automated or manual peritoneal lavage

61) A method of performing peritoneal lavage wherein changes inelectrocardiograph monitoring, electroencephalograph monitoring, pulseoximetry (either internally or peripherally), peritoneal cavitycompliance, intrathoracic pressure, intraperitoneal pressure, bladderpressure, rectal pressure, cardiac output, cardiac stroke volume,cardiac rate, blood flow (i.e. in superior mesenteric, celiac, renal orother arteries), pressure in veins (particularly those that empty intothe IVC, i.e. femoral vein), pressure in arteries (particularly thosedistal to the aorta, i.e. the femoral artery), blood oxygenation (i.e.in rectal mucosa, peripheral fingers and toes, etc.), whole body oxygenconsumption, pH and/or arterial p02 (or any other parameter that shows ameasurable change with increased peritoneal pressure) are monitored andmay be utilized to ensure safety of automated or manual peritoneallavage

62) An intravascular catheter containing one or more sensors which maydetect changes in electrocardiograph monitoring, electroencephalographmonitoring, pulse oximetry (either internally or peripherally), partialpressure of oxygen or C02, pH, temperature, blood pressure, centralvenous pressure, cardiac output, cardiac stroke volume, cardiac rate,blood flow (i.e. in superior mesenteric, celiac, renal or otherarteries), total circulating blood volume, pressure in veins(particularly those that empty into the IVC, i.e. femoral vein),pressure in arteries (particularly those distal to the aorta, i.e. thefemoral artery), blood oxygenation (i.e. in rectal mucosa, peripheralfingers and toes, etc.), whole body oxygen consumption, pH and/orarterial p02 (or any other parameter that shows a measurable change withintravascular volume overload) to ensure safety of manual or automatedintravascular infusion

63) A method of performing intravascular infusion wherein one or moresensors may detect changes in electrocardiograph monitoring,electroencephalograph monitoring, pulse oximetry (either. internally orperipherally), partial pressure of oxygen or C02, pH, temperature, bloodpressure, central venous pressure, cardiac output, cardiac strokevolume, cardiac rate, blood flow (i.e. in superior mesenteric, celiac,renal or other arteries), total circulating blood volume, pressure inveins (particularly those that empty into the IVC, i.e. femoral vein),pressure in arteries (particularly those distal to the aorta, i.e. thefemoral artery), blood oxygenation (i.e. in rectal mucosa, peripheralfingers and toes, etc.), whole body oxygen consumption, pH and/orarterial p02 (or arty other parameter that shows a measurable changewith intravascular volume overload) which may be used to regulate therate of infusion

64) The method of 63 wherein said rate of infusion may be maximized inthe absence of negative effects to the monitored parameters

65) The method of 63 wherein said rate of infusion may be reduced orhalted in the presence of negative effects to the monitored parameters

66) The method of 63 wherein said intravascular infusion may be utilizedto induce and/or maintain hypothermia or hyperthermia

67) The method of 63 wherein said intravascular infusion may be utilizedto optimize hydration and/or intravascular volume in any patientreceiving intravenous fluids

68) The method of 63 wherein said intravascular infusion may be utilizedto optimize hydration and/or intravascular volume in post-operativepatients

69) The method of 63 wherein said intravascular infusion may be utilizedto optimize hydration and/or intravascular volume in septic or otherintensive care patients

70) The method of 63 wherein said intravascular infusion may be utilizedto optimize hydration and/or intravascular volume with additional inputswhich may include sensor-based urine output detection

71) The method of 70 wherein said monitored parameters and urine outputinformation may be used, according to a hydration algorithm, to reportissues with intake or output and automatically correct these issues viaautomated changes to the rate of infusion and/or addition of diuretics

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 shows an automated infusion system in which infusion iscontrolled based on patient parameters sensed by multiple sensors.

FIG. 2 shows an automated infusion system in which a sensor controllinginfusion is separate from the infusion catheter.

FIG. 3 shows an automated infusion system in which sensing and infusionare performed with the same catheter.

FIG. 4 —Console with optional sensor lead (may be wireless).

FIG. 5 —Sensor-based Urine Output Measurement.

FIG. 6 —Console with automated infusion therapy system.

FIG. 7 —Volume-sensing Urine Receptacle with Dock.

FIG. 8 —Volume-sensing Urine Receptacle—RFID Embodiment.

FIGS. 9A-9D—Side view of the sensor incorporated into the instrument.

FIGS. 10A-10E—Side view of the sensor incorporated into removableinsertion trocar.

FIGS. 11A-11E—Side view of the sensor Incorporated into removablesheath.

FIGS. 12A-12C—Side view of the External Reader attached to AccessDevice.

FIGS. 13A-13D—Side view of the continuous reader incorporated intoAccess Device (trocar embodiment).

FIGS. 14A-14D—Side view of the intermittent reader incorporated intoAccess Device (trocar embodiment).

FIGS. 15A-15E—Side view of the sensor incorporated into access device(shown as catheter with insertion trocar).

FIG. 16 —Intravenous fluid flow automated by sensors.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-3 show embodiments of the invention wherein intravenous fluiddelivery may be automated, or manually adjusted, based on feedback fromone or more sensors. In these embodiments, the infusion catheter mayhave a sensor to aid in insertion, but this is not necessary for thisinvention.

In one embodiment, the infusion catheter also is used to detect theparameters used to optimize therapy. FIG. 1 shows an infusion systemwith an infusion controller 10 operably connected to an intravenousinfusion catheter 12 via an infusion line 14. Infusion catheter 12 alsohas a sensor (not shown) attached to or associated with it to monitor apatient parameter. The sensor also communicates with controller 10either through line 14 or via some other communication channel. Suitablepatient parameters include electrocardiograph monitoring,electroencephalograph monitoring, pulse oximetry (either internally orperipherally), blood pressure, central venous pressure, cardiac output,cardiac stroke volume, cardiac rate, blood flow (e.g., in superiormesenteric, celiac, renal or other arteries), total circulating bloodvolume, pressure in veins (particularly those that empty into theinferior vena cava, e.g., femoral vein), pressure in arteries(particularly those distal to the aorta, e.g., the femoral artery),blood oxygenation (e.g., in rectal mucosa, peripheral fingers and toes,etc.), whole body oxygen consumption, pH, arterial pO₂, or any otherparameter that shows a measurable change with intravascular volumeoverload.

As shown in FIG. 1 , additional catheters, here envisioned as aperipherally inserted central catheter (PICC) 16 and/or a peritonealcatheter 18, or additional sensors on infusion catheter 12 may be usedto monitor these or other parameters, and to optimize the infusion rateand achieve euvolemia without fluid overload or dehydration. Flow offluid and/or a fluid/solid mixture (e.g., an ice slurry) to catheters 16and/or 18 is controlled by controller 10 through lines 14, 15 and/or 17,respectively. The information from the sensors may then be transmittedto central controller 10, which integrates all of this information todetermine the flow of intravenous fluid through catheter 12 and/orcatheter 16 and flow of peritoneal fluid through catheter 18. Thisinformation may be used to achieve or maintain euvolemia (e.g., insepsis, hemorrhagic shock, etc.) or to maximize infusion for delivery ofa therapeutic agent, e.g., chilled fluid and/or solids to achievehypothermia. Alternatively, catheters 16 and 18 may be used with sensorsto obtain patent information, and fluid may be infused into the patientsolely through catheter 16 or catheter 18. In yet further embodiments,the depth of hypothermia and/or rate of hypothermia induction orrewarming may be tailored based on intracranial pressure sensor(s) (notshown) communicating with controller 10 via communication line 35. Thissystem and method may be used with any method of inducing hypothermia(e.g., cooling blankets, intravascular catheters, intravenous fluidinfusion, peritoneal lavage, etc.) so long as the change in temperature,particularly rewarming, is controlled at least in part by anintracranial pressure sensor.

The sensor or sensors, whether cables/catheters or percutaneousmonitoring technologies, and whether wired or wireless, may also beseparate from the infusion line so long as the information from thissensor or sensors is transferred to the control unit in order tooptimize fluid flow. Thus, as shown in FIG. 2 , the patient parametersensor may be associated with PICC 24 and communicate with controllervia line 26, and infusion to the patient may be via line 22 and infusioncatheter 20, as controlled by controller 10. In some embodiments, ofcourse, sensing and infusion may be performed through a single catheter,such as PICC 30, and controlled by controller 10 through lines 32 and34, as shown in FIG. 3 . In some embodiments, the infusion andmonitoring device of the current invention may incorporate an accesssensor, such as that described in a commonly owned patent application,U.S. patent application Ser. No. 12/098,355, filed Apr. 4, 2008, titled“Device And Method For Safe Access To A Body Cavity”.

One example of such a device is a peripheral venous, central venous orarterial catheter that is capable of maintaining hydration withoutcausing fluid overload. The catheter may incorporate a sensor that maydetect central venous pressure, total circulating blood volume,peripheral venous pressure, cardiac output or osmolarity, and/or soluteconcentrations (e.g., chloride, sodium, etc.) in order to prevent fluidoverload. The sensor may also be external to the catheter, so long asthe output of said sensor is capable of controlling fluid flow throughthe catheter. In this embodiment, fluid flow is controlled by the outputof the sensor, which is integrated by a fluid flow control unit whichalters the rate of fluid flow based on this output. This embodiment mayallow the user to bolus large volumes of fluids or solids into thevascular space in order to rehydrate, induce hypothermia or reversehypothermia, or deliver a therapeutic agent or maintain blood pressurein sepsis.

In addition, this technology may provide a fully automated mechanism tooptimize fluid flow into the vessel without fluid overloading thepatient. Without this automated fluid delivery coupled to hemodynamicparameter monitoring, the patient is in danger of dehydration or fluidoverload from infusion of fluid into any body cavity. This technologymay also be applied to liquid or solid infusion into any body cavity orspace in so long as the fluid flow is automated based on feedback fromsensors within the body (possibly incorporated into the catheter itself)in order to optimize the volume of infusion.

This device and method of automating fluid flow based on hemodynamicsensor-based feedback may also be used to generate intravenoushypothermia. In its current state, IV hypothermia induction is limiteddue to concerns of fluid overload. If the hemodynamic parameters of thepatient can be measured and fluid flow directly or indirectly controlledbased on the output of these measurements, the volume of fluid can bemaximized while ensuring hemodynamic instability. In this embodiment,the sensor may be incorporated within the catheter, and fluid flow intothe vasculature may be tailored based on central venous pressure, totalcirculating blood volume, peripheral venous pressure, cardiac output orosmolarity, and/or solute concentrations (e.g., chloride, sodium, etc.)in order to prevent fluid overload.

In one embodiment, the fluid infusion catheter also may function as athermodilution cardiac output sensor such that the same fluid that isused to generate hypothermia may also be used to detect cardiac output.This information may then be relayed, either directly or indirectly,back to the fluid infusion controller to increase, decrease or even haltfluid flow based on these parameters. For example, if cardiac output islow and venous pressure or total circulating volume is low, the patienthas a low circulating volume and large volumes of fluid may be safelydelivered. If the cardiac output is normal, fluid may also be safelydelivered, but the cardiac output must be monitored to ensure that itdoes not begin to decrease (an indication of fluid overload). Bloodflow, as detected by, for instance, thermodilution may be determined ina peripheral vessel as well. These data, while relatively useless ontheir own in a clinical setting due to variability in peripheral bloodflow, may provide a baseline flow profile which may be rechecked overtime in order to compare flow within that individual vessel to thebaseline flow. Relatively improved flow may be correlated to improvedcardiac output, while a relative reduction in flow may be correlated tofluid overload.

This same system may be used to infuse normal fluids or hypothermicfluids to sepsis patients or patients requiring intensive maintenance oftheir hemodynamic status. Sepsis patients that are aggressivelymonitored do much better than those that are not. Aggressive monitoringis very nurse-intensive, however. A system that provides automatedoptimal fluid infusion based on sensed parameters to ensure that fluidoverload does not occur and that fluid infusion is not insufficientwould be an improvement over current methods of treating sepsispatients. The devices and methods for automated sensor-based input tocontrol fluid flow to a patient may be applicable to a wide range ofconditions and should not be limited to the narrow scope of theconditions requiring fluid infusion described here.

The logic controller of the present invention may provide improvedsafety by monitoring for any of the deleterious changes expected withexcess fluid flow, e.g., into the peritoneal cavity or vascular space.Examples of monitored parameters that may signal a warning orautomatically result in an adjustment to rate of fluidinfusion/extraction and/or fluid temperature include: electrocardiographmonitoring, electroencephalograph monitoring, pulse oximetry (eitherinternally or peripherally), peritoneal cavity compliance, intrathoracicpressure, intraperitoneal pressure, intraperitoneal pressure waveforms,bladder pressure, rectal pressure, cardiac output, cardiac strokevolume, cardiac rate, total circulating blood volume, blood flow (e.g.,in superior mesenteric, celiac, renal or other arteries), pressure inveins (particularly those that empty into the IVC, e.g., femoral vein),pressure in arteries (particularly those distal to the aorta, e.g., thefemoral artery), blood oxygenation (e.g., in rectal mucosa, peripheralfingers and toes, etc.), whole body oxygen consumption, pH and arterialpO₂ and any other parameter that shows a measurable change once theperitoneal or vascular spaces have been overloaded.

These parameters in particular have been found to change with increasesin peritoneal pressure, with significantly negative impact on eachparameter found at 40 mmHg. Thus, monitoring for these changes inconjunction with a peritoneal infusion catheter of the present inventionwill allow for even greater safety with peritoneal infusion. Theseparameters may be measured a variety of ways and the data transmittedeither wirelessly or via wires to the logic controller in order to alertthe healthcare provider or to automatically adjust the fluidflow/temperature in order to optimize both the flow of the peritonealfluid and patient safety.

FIG. 4 illustrates a console 40 with optional sensor lead 44 which mayor may not be wireless. The console itself may record output/input data42. This data may be held in memory, printed or directly transmitted toa centralized data collection server. Said console may connect to theurine receptacle 46 to determine urine output either via a wire orwirelessly.

FIG. 5 illustrates sensor-based Urine Output Measurement. In thisinstance, the console 50 or RFID reader can trigger alert if urineoutput is too low or too high over a set period of time. May also haveintravenous infusion capabilities to provide input and output data andtailor delivery of fluids and/or medicines (ie diuretics) via anautomated system based on the urine output feedback. The device mayinclude an optional Docking Station 54—ideally reusable, may connect toreceptacle 52 and transmit data to control unit either via wires or,ideally, wirelessly. May also measure urine level via weight, etc.Optional Urine Level Sensors 56 may report level of urine viaconductivity, resistance, impedance, etc. Sensors may also continuouslyor intermittently detect bacteria, hemoglobin or other substances ofinterest in urine. Urinary catheter 58 is also shown.

FIG. 6 illustrates a console 60 with automated infusion therapy system.Console may integrate patient data, ie fluids received, urine outputrecorded, etc. to automate therapy, ie delivery of fluids or LASIX ifthe pt is dehydrated or fluid overloaded respectively. May also triggerlocal alert (ie beeping) and centralized alert (ie system alarm) ifurine output drops too low. The console may also integrate a fluidinfusion or medicine infusion capabilities, ie an IV infusion pump, andmay adjust infusion rates based on this data or data acquired from othersensors in an automated fashion. The console may communicate wirelessly,as well, to these and any other sensors within the body. Infusioncatheter 62 is also shown—may deliver drugs or fluid based on urineoutput and other parameters. Urinary catheter 64 is also shown.

FIG. 7 illustrates a volume-sensing Urine Receptacle with reusablecommunicating and/or sensing element. The receptacle 70 itself maydetect urine output based upon level at which sensors are triggered—iehave hash-marks represent electrical contacts and when an electricalpath is made between two contacts, and all contacts below, the level canbe reported at that level. May be electrical, optical, chemical ormechanical sensors. May also contain diffuse or discrete sensing areasthat may detect the presence of absence of certain materials ofinterest, ie hemoglobin, protein, glucose, bacteria, blood, leukocyteesterase, etc. either intermittently or continuously. May report anyand/or all of this information to the console, locally (via beeping,etc.) or centrally via piping data to a central information collectionarea. Alerts triggered if urine output drops below 30 cc/hr inpost-operative setting or any otherwise defined threshold. May also bedisposable and connect to the docking station 72 which may communicatethe data from said, receptacle wirelessly. The docking station may beconnected anywhere on said receptacle, or optionally, not included atall. If a docking station is used, it may detect urine output basedsimply upon weight or pressure applied to base. May contain disposableor, ideally, durable optical, electrical or chemical sensors capable ofsensing glucose, electrolytes, bacteria, hemoglobin, blood, etc. Mayinterface with specifically designed area of the urine receptacle toallow for this measurement—ie an optically clear window for opticalmeasurement of blood, etc. May also fasten onto the urine receptacle inany position so long as it engages the receptacle. This or thereceptacle itself may contain an inductive antenna and/or RFIDcapabilities to allow for wireless querying and reporting of the levelof urine or other fluid collection.

FIG. 8 illustrates a volume-sensing Urine Receptacle 80 with RFIDcapabilities. This embodiment may contain RFID circuitry to collect andtransmit data directly from within the receptacle to a RFID Reader. Whenqueried by the RFID reader may simply detect impedance, resistance,capacitance or any other electrical or nonelectrical property to detectthe urine level and report this back to the reader. Reader may thentrigger alert if urine output is high or low. The RFID chip may becapable of detecting changes in optical, chemical, electrical, acousticor mechanical properties, as well. May be active or passive RFID and maycontain antenna in any position and, ideally, may transmit a uniquesignal to identify the receptacle to the reader and allow multiplereceptacles to be queried at once. The RFID chip may incorporate a smallbattery (to extend its range) in an active RFID embodiment or may bepassive in nature and be powered solely by the transmissions from saidRFID reader. The RFID Reader 82 may query device from a distance towirelessly check the urine output level or may be centralized to queryall receptacles within a unit, floor or hospital and issue an alert ifurine output drops too low (or is too high). May record urine output, aswell, and replace the individual unit consoles illustrated in FIGS. 1-3. The RFID reader may also report data from other sensors within saidsystem, including bladder temperature or presence of certain materialswithin the urine, ie blood, hemoglobin, leukocyte esterase, otherindicators of bacterial infection, protein, glucose, etc.

In another embodiment, a urinary catheter capable of sensing physiologicparameters is envisioned. Additional sensing capabilities may include:blood pressure, oxygen saturation, pulse oximetry, heart rate, EKG,capillary fill pressure, etc. In particular, the incorporation of pulseoximetry technology to allow for blood oxygen concentration orsaturation determination with a urinary catheter is envisioned. Thisdevice may function by incorporating pulse oximetry capabilitiesanywhere along the length of the catheter, but ideally the sensor orsensors will be contained within the tubing of the device to ensureapproximation to the urethral mucosa. With this invention, thehealthcare provider will be able to decompress the bladder with aurinary catheter and obtain pulse oximetry data in a repeatable andaccurate manner. The power source for this device may be incorporatedwithin the urinary drainage bag or within the catheter itself. Ideally,the pulse oximeter will be reusable and the catheter interface will bedisposable wherein the pulse oximeter is simply reversibly attached tothe disposable catheter and removed once measurements of oxygen are nolonger desired. The urinary catheter, then, may contain an opticallytransparent, or sufficiently transparent, channel for the oximetrysignal, ie a fiber-optic cable, transparent window, etc., and aninterface for the reusable oximeter and otherwise be a standard urinarycatheter. This method and device for urethral pulse oximetry may be usedin conjunction with any of the other embodiments detailed herein or maybe a stand-alone device in and of itself.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

-   -   I. Device: Automated Urine Output Measurement    -   II. Indications for Use (IFU): Any condition requiring urine        output monitoring    -   III. Preferred Methods for Use:        -   a. Upon placement of a Foley catheter, ideally with a            temperature sensor or intra-vesicular sensor/probe, the            receptacle component of the Automated Urine Output            Measurement system is attached to the output tubing        -   b. The receptacle is attached to a stationary object, or the            patient themselves and the data ID for the receptacle is            entered into the RFID reader, which may be centralized and            capable of querying all Automated Urine Output Measurement            receptacles within a predefined range or area        -   c. The RFID reader then queries, and optionally powers, the            RFID chip within the receptacle which reports the fluid            level based on the impedance, conductance or other            electrical properties of sensors within the bag        -   d. This data is transmitted to centralized data collection            point where it may be monitored by an individual        -   e. If certain thresholds are not met, ie 30 cc/hr urine            output, local alarms (ie a beeping) or remote alarms (ie an            alert at the centralized monitoring station) may be            triggered        -   f. The information obtained from the receptacle may be used            in a feedback loop to automate the delivery and/or            extraction of fluids and/or medicines from the patient to            optimize therapy        -   g. In conjunction with urine output measurement the            healthcare professional may also attach an oximeter to a            specifically designed site on the urinary catheter in order            to obtain pulse oximetry measurements        -   h. Once the measurements have been completed, the oximeter            may be reused (or disposed of) and the urinary catheter            either removed or kept in place

In its preferred embodiment, the novel access system involves the use ofa puncturing instrument in conjunction with a sensor at, or near, thetip of the instrument. This sensor may be capable of detecting changeswithin its environment in order to report that it has passed from thesubcutaneous tissues into the desired cavity, space or tissue. Forexample, a novel peritoneal access catheter is envisioned which iscapable of detecting differences between the vascular, extraperitoneal,intestinal and intraperitoneal spaces. This sensor may detect I) changesin the physical properties surrounding the instrument such as pressure,acceleration, forces or other physical properties, 2) chemical changessurrounding the instrument, ie the presence or absence of compounds suchas albumin, hemoglobin, glucose or the pH or other chemical properties,or 3) changes in the electrical properties such as conductance,resistance, impedance, capacitance, etc. of the tissues 4) changes inthe acoustic or vibratory properties of the tissues, 5) changes inoptical properties such as refraction of light within the tissue, or 6)changes in any other parameter that is able to be sensed via a sensorplaced on, in, within or otherwise attached to or in communication withsaid instrument.

In any of the embodiments, as well, the sensing element of said devicemay be incorporated in instrument itself, may be introduced along withthe instrument or may be external to the instrument and communicatethrough a channel in said instrument. In the ideal embodiment, thesensor is incorporated into either in the instrument or its introducerand is able to provide immediate, definitive feedback that the correctbody cavity has been accessed. For example, the electrical properties ofblood are different from that of air, the epidermis, the subcutaneousspace, the fascia and the adventia of the vessel. Thus, in accessing thefemoral artery, for instance, one can slowly insert the arterial accessdevice (ie a catheter with a sharp insertion trocar/needle) whichincorporates a sensor in the catheter or insertion trocar/needle (inthis case electrical) which will immediately report a change in thesensed parameter (in this case inductance, resistance, capacitance,etc.) indicating that the vessel has been entered. This same reading canthen them be monitored continuously as the instrument is manipulated (iethe catheter is slid over the trocar/needle into the vessel) to ensurethat the instrument does not migrate during manipulation and remainswithin the desired space.

Another embodiment comprises the use of heat differentials to guide acatheter/needle to the appropriate space/tissue. For example, by placinga cold pack on the skin over the femoral artery, a temperaturedifferential will exist with the warmest location being in theintravascular space. A temperature sensing catheter can be guided to thewarmest location which would be inside the vessel.

This sensing technique may be employed with virtually any invasiveinstrument to ensure correct placement via detection of changes in anyof the aforementioned parameters (i.e. physical, chemical, thermal,electrical, acoustic/vibratory, optical or other parameter capable ofbeing sensed) with the only requirement being that the target tissue orspace within the body must have a sufficiently distinct sensor readingthat it may be distinguished from its surrounding tissues. Theseinvasive instruments may include, but are not limited to instruments,catheters or devices intended to access the following spaces/tissue:peritoneal cavity or fluid (ie paracentesis or peritoneal lavage),vascular fluid or space (arterial catheter, intravenous catheter, etc.),cerebrospinal fluid or space, pleural or pulmonary fluid or space (iechest tubes), pericardial or cardiac space or tissue, urologic fluid orspace (ie suprapubic catheters), gynecologic access (ie fallopian tubesor ovaries), gastrointestinal fluid or space (ie nasogastrostomy orgastrostomy tubes), ocular or bulbar tissues or spaces, neurologicaltissue or space (ie brain biopsy instruments), pathological tissue orspace (ie abscess, hematoma, cyst, pseudocyst), bone marrow tissue orspace, or any other tissues or spaces that may be accessed minimallyinvasively, percutaneously or through a natural orifice.

The sensing element may be disposable or reusable. The sensing elementmay be incorporated reversibly or irreversibly into the instrumentitself, into the instrument's sheath, into the instrument's trocar, orkept external to said instrument with movement of gases, fluids orsolids down the length of the instrument to the externally locatedsensor continuously or upon activation. Said sensor may also communicatewirelessly from the instrument to an external receiver removing therequirement for a tethering cord and allowing for a disposable andreusable component. The controller/reader may alert the user that accesshas been obtained through tactile, auditory, visual or any other_stimuli. The sensing may occur continuously or only upon command by theuser (ie once they suspect that they are in the tissue or cavity).

FIGS. 9A-9D show side views of the sensor incorporated into theinstrument. In this image, the instrument 91 (in this case a needle ortrocar) contains a sensor 92 at its tip which may intermittently orcontinuously provide information to the user to indicate plane ofinsertion. In this illustration, the instrument is shown passing throughthe subcutaneous tissues and muscular layers 93 and entering the cavity95 without harming or penetrating the tissues beneath. Examples wherethis illustration apply include: peritoneal cavity access, pleuralcavity access, cerebrospinal cavity access, etc. In each of these cases,entrance into the space may be required but the underlying tissues (theintestines/liver, lungs and spinal cord/brain, respectively) aresensitive and a sensing technology to prevent over-insertion would be asignificant advance in the state of the art. In addition to the sensorsdetection of 1) changes in the physical properties surrounding theinstrument such as pressure, acceleration, forces or other physicalproperties, 2) chemical changes surrounding the instrument, ie thepresence or absence of compounds such as albumin, hemoglobin, glucose orthe pH or other chemical properties, or 3) changes in the electricalproperties such as conductance, resistance, impedance, capacitance, etc.of the tissues 4) changes in the acoustic or vibratory properties of thetissues, and/or 5) changes in optical properties such as refraction oflight within the tissue to detect instrument entrance into the cavity,6) and/or changes in the thermal properties of the tissues the samesensor, or another sensor, may be capable of detecting other componentsthat signal an issue may have occurred during entry. For example, withthe peritoneal catheter example, the sensor, or another sensor, may beable to detect the presence of fecal matter or blood which wouldindicate that even though the cavity may have been entered, the cathetermay been over-inserted or is not in its correct position. This positivefeedback related to instrument entry and negative feedback with respectto possible incorrect positioning of the instrument, in combination,provide confidence to the user not only that the correct cavity, spaceor tissues have been accessed but that no complications have arisenduring the access procedure.

One example of this embodiment is a peritoneal access catheter with anelectrical inductance sensor at its tip. The subcutaneous space has adifferent inductance compared to the peritoneal space which also has adifferent inductance than the intestinal lumen. In accessing theperitoneal cavity, then, the catheter may be advanced until thesubcutaneous tissue inductance readings change to the peritoneal cavityinductance levels. Once the peritoneal cavity is sensed, based on thechange in electrical properties, the catheter then provides feedbackthat the cavity has been accessed. In the event that the catheter isover-inserted into the bowel, the inductance will be dramatically lowerthan that found in the subcutaneous tissue or peritoneal space and thiscomplication can be rapidly reported. In addition, iron-rich blood has ahigher inductance than any of the other tissues and exposure toconcentrated blood can be quickly reported if the catheter experiencesthis fluid. The cutoff may be set, as well, so that dilute blood doesnot trigger the sensor since minor capillaries may be ruptured in thenormal access procedure. This same technique may be used, in reverse, topurposefully access the vascular space. In fact, most tissues havecharacteristic electrical properties and virtually any tissue, cavity orspace may be accessed through monitoring for this signal duringinstrument insertion. This is just one embodiment and the access devicemay be used to access any body tissue, space, or cavity and may do sowith feedback from any of the sensors detailed above or any othersensing technology.

FIGS. 10A-10E are side views of the sensor incorporated into removableinsertion trocar. In this instance, the sensor is not incorporated intothe catheter itself, but is instead coupled with an insertion tool, inthis case a central insertion trocar 107. Once the tissue, space, orcavity has been accessed, the insertion trocar may be removed 8 and thecatheter advanced or left in place to allow access to the tissue orspace for the intervention.

FIGS. 11A-11E illustrate side views of the sensor 118 incorporated intoremovable sheath 119. In this embodiment, the sheath sensor 118 reportsentry into the space then the access instrument 1110 is left in thecavity 1111 while the insertion sheath 119 is removed. This embodimentis particularly appealing in instance where, once access is confirmed,future confirmation is not required since the sensor is removed alongwith the sheath. This embodiment is most useful, then, in instanceswhere the instrument 1110 will remain in place for a long period of time(i.e. an implantable device with long-term action) or where the desiredprofile of the instrument 1110 is sufficiently small that inclusion ofthe sensor 118 into the instrument 1110 itself becomes technicallychallenging and economically impractical.

FIGS. 12A-12C demonstrate side views of the External Reader attached tothe access device. In this embodiment, the external reader 1212 may havea display 1213 or some other form of alert to let the user know that theaccess device has entered the correct cavity, or in which cavity thesensor currently resides. In its optimal embodiment, the sensor willprovide information related to the tissue surrounding the sensorcontinuously and in real-time so that informed decisions to advance orretract the access device may be made. This illustration depicts thesensor incorporated within a removable insertion trocar, but it isimportant to note that this external reader and any other method ofreporting device position to the user may be used with any of thesensing technologies described in this text or illustrated in thesedrawings.

FIGS. 13A-13D illustrate side-views of the continuous readerincorporated into access device. In this embodiment, the integratedreader 1314 may have a display 1315 or some other form of alert to letthe user know that the access device has entered the correct cavity, orin which cavity the sensor currently resides. As with the externalreader of FIG. 12 , in its optimal embodiment, the sensor will provideinformation related to the tissue surrounding the sensor continuouslyand in real-time so that informed decisions to advance or retract theaccess device may be made. This illustration depicts the sensorincorporated within a removable insertion trocar, but it⋅ is importantto note that this external reader and any other method of reportingdevice position to the user may be used with any of the sensingtechnologies described in this text or illustrated in these drawings. Aswith any of the embodiments described, the sensing device (here shown asthe insertion trocar), may be disposable or reusable.

FIGS. 14A-14D illustrate side-views of the intermittent readerincorporated in.to the access device. In this embodiment, the integratedreader may have a display or some other form of alert to let the userknow that the access device has entered the correct cavity, or in whichcavity the sensor currently resides. As with the integrated reader ofFIG. 13 , in its optimal embodiment, the sensor will provide informationrelated to the tissue surrounding the sensor, but will do so only whenactivated, in this instance via deployment of a reversible a push-button1416 at the end of the insertion device. This intermittent reading maygive exact tissue location information, as well, and may be deployedrepeatedly. This embodiment is particularly appealing for sensingtechnologies, ie optical, that may produce heat or other potentiallyharmful byproducts and should, ideally, only be activated for briefperiods of time. As with other embodiments, informed decisions to theadvancement or retraction of the access device may be made. Thisillustration depicts the sensor incorporated within a removableinsertion trocar, but it is important to note that this external readerand any other method of reporting device position to the user may beused with any of the sensing technologies described in this text orillustrated in these drawings. As with any of the embodiments described,the sensing device (here shown as the insertion trocar), may bedisposable or reusable.

FIGS. 15A-15E illustrate side-views of the sensor incorporated into acatheter, this time again with the central trocar embodiment. In thisembodiment, as with FIG. 11 , a sensor may be incorporated into theexternal sheath surrounding an insertion trocar. In contrast, though, inthis embodiment the insertion trocar may be removed and thesensor-containing sheath 1517 may remain within the cavity. Thisembodiment is particularly useful for catheter insertion and advancement(as illustrated in successful illustration from top to bottom). Usingthe sensor at the tip, catheter position may be continuously orintermittently assessed while it is advanced thereby ensuring that thecatheter is not only in position when the trocar is removed, but that itremains within the correct cavity while it is advanced. The catheter orsheath may be single or multiple lumen catheter and may employ a sensorincorporated into instrument or an external sensor. The catheter mayalso use additional sensors or lumens or other communication means toexternal sensors in order to provide the desire intervention or therapy.One preferred embodiment of this device describes a method of accessingthe peritoneal cavity with a catheter. In this embodiment, thesensor-containing catheter may be advanced using the central trocar as astiffening element. This insertion procedure may employ a bluntdissecting instrument or may utilize the Seldinger technique (ormodification thereof). Once the catheter or sheath begins to movethrough the tissues, though, the sensor at the tip may report positionto the user, either intermittently or—ideally—continuously, indicatingwhich tissues are surrounding the sensor. Once the peritoneal cavity hasbeen accessed, in this embodiment, the reader, either external orintegrated within the access device, reports that the cavity has beenaccessed via visual, auditory or tactile stimuli. The central trocar maythen be removed and the catheter advanced, once again during continuousmonitoring by the sensor in its optimal embodiment. If the cathetermoves from the peritoneal cavity (ie into subcutaneous tissues, muscle,bowel or any other organ) or becomes surrounded by another fluid (blood,urine, etc.) then the sensor may report the change and indicate to theuser that the device is no longer optimally placed and that furtherintervention (whether it be simply adjusting the catheter or performingfurther investigation) is required. Using this device and method, theuser may ensure precise and consistent access to the peritoneal cavitynot only upon insertion but for the duration of the placement of thedevice and through any required manipulations.

FIG. 16 details the embodiment wherein intravenous fluid delivery may beautomated, or manually adjusted, based on feedback from one or moresensors. In this embodiment, the infusion catheter 1618 may preferablyhave a sensor to aid in insertion, but this is not necessary for thisinvention. In the ideal embodiment, the infusion catheter also is usedto detect the parameters used to optimize therapy, namelyelectrocardiograph monitoring, electroencephalograph monitoring, pulseoximetry (either internally or peripherally), blood pressure, centralvenous pressure, cardiac output, cardiac stroke volume, cardiac rate,blood flow (i.e. in superior mesenteric, celiac, renal or otherarteries), total circulating blood volume, pressure in veins(particularly those that empty, into the IVC, i.e. femoral vein),pressure in arteries (particularly those distal to the aorta, i.e. thefemoral artery), blood oxygenation (i.e. in rectal mucosa, peripheralfingers arid toes, etc.), whole body oxygen consumption, pH, arterialp02, or any other parameter that shows a measurable change withintravascular volume overload. Additional catheters, here envisioned asa peripherally inserted central catheter (PICC) 1619, or bladdercatheter 1620, or additional sensors on this infusion catheter may beused to monitor these, or other, parameters, though to optimize theinfusion rate and achieve euvolemia without fluid overload ordehydration. This information may then be transmitted to a centralcontroller 1621, which integrates all of this information to determinethe flow of intravenous fluid. This may be used to achieve or maintaineuvolemia (ie in sepsis, hemorrhagic shock, etc.) or to maximizeinfusion for delivery of a therapeutic agent, i.e. chilled fluid and/orsolids to achieve hypothermia. The sensor or sensors, whethercables/catheters or percutaneous monitoring technologies—wired orwireless, may also be disparate from the infusion line so long as theinformation from this sensor or sensors is transferred to the controlunit in order to optimize fluid flow. In this embodiment, as well, thedevice of the current invention may or may not incorporate the accesssensor, but may utilize sensors to optimize therapy. One example of sucha device is a peripheral venous, central venous or arterial catheterthat is capable of maintaining hydration without causing fluid overload.Said catheter may incorporate a sensor which may detect central venouspressure, total circulating blood volume, peripheral venous pressure,cardiac output or osmolarity, and/or solute concentrations (ie chloride,sodium, etc.) in order to prevent fluid overload. The sensor may also beexternal to said catheter, so long as the output of said sensor iscapable of controlling fluid flow through the catheter. In thisembodiment, said fluid flow is controlled by the output of said sensorwhich is integrated by a fluid flow control unit which alters the rateof fluid flow based on this output. This embodiment may allow the userto bolus large volumes of fluids or solids into the vascular space inorder to rehydrate, induce hypothermia or induce hypothermia, or delivera therapeutic agent or maintain blood pressure in sepsis. In addition,this technology may provide a fully automated mechanism to optimizefluid flow into the vessel without fluid overloading the patient.Without this automated fluid delivery coupled to hemodynamic parametermonitoring, the patient is in danger of dehydration or fluid overloadfrom any vascular infusion. This technology may also be applied toliquid or solid infusion into any body cavity or space in so long as thefluid flow is automated based on feedback from sensors within the body(ideally incorporated into the catheter itself) in order to optimize thevolume of infusion. This device and method of automating fluid flowbased on hemodynamic sensor-based feedback may also be used to generateintravenous hypothermia. In its current state, IV hypothermia inductionis limited due to concerns of fluid overload. If the hemodynamicparameters of the patient can be measured and fluid flow directly orindirectly controlled based on the output of these measurements, thevolume of fluid can be maximized while ensuring hemodynamic instability.In this embodiment, the sensor may be, ideally, incorporated within thecatheter and fluid flow into the vasculature may be tailored based oncentral venous pressure, total circulating blood volume, peripheralvenous pressure, cardiac output or osmolarity, and/or solute.concentrations (ie chloride, sodium, etc.) in order to prevent fluidoverload. In its optimal embodiment, the fluid infusion catheter alsomay function as a thermodilution cardiac output sensor such that thesame fluid that is used to generate hypothermia may also be used todetect cardiac output. This information may then be relayed, eitherdirectly or indirectly, back to the fluid infusion controller toincrease, decrease or even halt fluid flow based on these parameters, ieif cardiac output is low and venous pressure or total circulating volumeis low, the patient has a low circulating volume and large volumes offluid may be safely delivered. If the cardiac output is normal, fluidmay also be safely delivered, but the cardiac output must be monitoredto ensure that it does not begin to decrease (an indication of fluidoverload). This same system may be used to infuse normal fluids orhypothermic fluids to sepsis patients or patients requiring intensivemaintenance of their hemodynamic status. Sepsis patients that areaggressively monitored do much better than those that are not. This isvery nurse-intensive, though, so a system that provides automatedoptimal fluid infusion based on sensed parameters to ensure that fluidoverload does not occur and that fluid infusion is not insufficient.This device providing for the automated sensor-based input to controlfluid flow and method of delivering fluid using this system may beapplicable to a wide range of conditions and should not be limited tothe narrow scope of the conditions requiring fluid infusion describedhere.

While this description has focused largely on the method and device forperitoneal insertion, this same procedure and method may be used toaccess any body cavity, tissue or space reliably and consistently withconfidence. In using this technology, clinician's may be confident thattheir instrument resides in its desired space without the requirementfor complex instrumentation or costly imaging techniques. For example,in its preferred embodiment this method and device may be used inconjunction with any access device that currently requires imaging toconfirm placement, but without the need for ionizing radiation. Examplesof such devices include nasogastric tubes, central venous lines, chesttubes, feeding tubes, etc.

Communications between the sensor and display or instrument control unitmay also be done wirelessly, ie via RFID or Bluetooth. In the instancewhere the catheter is a dual lumen catheter, one lumen may be used forfluid delivery while the other may be used for fluid return and atemperature and/or pressure sensor may be incorporated along its length,ideally closer to the fluid return tubing than the fluid deliverytubing.

Furthermore, the logic controller of the present invention may provideimproved safety by monitoring for any of the deleterious changesexpected with excess fluid flow i.e. into the peritoneal cavity orvascular space. Examples of monitored parameters that may signal awarning or automatically result in an adjustment to rate of fluidinfusion/extraction and/or fluid temperature include: electrocardiographmonitoring, electro-encephalograph monitoring, pulse oximetry (eitherinternally or peripherally), peritoneal cavity compliance, intrathoracicpressure, intraperitoneal pressure, bladder pressure, rectal pressure,cardiac output, cardiac stroke volume, cardiac rate, blood flow (i.e. insuperior mesenteric, celiac, renal or other arteries), pressure in veins(particularly those that empty into the IVC, i.e. femoral vein),pressure in arteries (particularly those distal to the aorta, i.e. thefemoral artery), blood oxygenation (i.e. in rectal mucosa, peripheralfingers and toes, etc.), whole body oxygen consumption, pH and arterialp02 and any other parameter that shows a measurable change once theperitoneal or vascular spaces have been overloaded. These parameters, inparticular, have been found to change with increases in peritonealpressure with significantly negative impact on each parameter found at40 mmHg, thus monitoring for these changes in conjunction with theperitoneal infusion catheter of the present invention will allow foreven greater safety with peritoneal infusion. These parameters may bemeasured a variety of ways and the data transmitted either wirelessly orvia wires to the logic controller in order to alert the healthcareprovider or to automatically adjust the fluid flow/temperature in orderto optimize both the flow of the peritoneal fluid and patient safety.

While most of these embodiments have been written focusing on certainembodiments, i.e. a catheter technology, the invention may be used withany instrument that demands precise access to tissues, body cavities orspaces and/or requires automated, sensor-based intervention or therapy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

-   -   I. Device: Peritoneal Access Safety System (PASS)    -   II. Indications for Use (IFU): Any intervention requiring        peritoneal access    -   III. Preferred Methods for Use:        -   a. Upon presentation with a condition fitting the criteria            for IFU, the device of the present invention will be            obtained and the patient will be prepared for paracentesis.        -   b. The access system will then be advanced through the            subcutaneous and deeper tissues slowly while the reader is            closely observed to indicate the depth of the puncture.        -   c. The reader indicates depth of puncture, ideally, based on            the unique electrical signature (impedance, resistance,            capacitance, etc.) of the tissue surrounding the sensr.        -   d. Once the reader indicates that the cavity has been            accessed, advancement ceases and the central insertion            trocar may be removed and/or the catheter advanced.        -   e. The soft, blunt-tipped catheter may be advanced slowly,            once again while the position reader is observed.        -   f. Once the catheter has been inserted to its desired depth            the position is once again checked and, if the catheter has            been correctly inserted, the intervention is performed.        -   g. If the catheter position is not correct, corrective            measures may be taken to ensure correct positioning prior to            any intervention.        -   h. Optionally, but preferably, the position sensor may            continuously monitor position to ensure that the catheter            does not migrate during the intervention.        -   i. Optionally, but preferably, as well, the sensor may be            used to indicate the occurrence of complications (ie            presence of blood) with any intervention        -   j. Optionally, but preferably, as well, the catheter may            contain other sensor technology, ie pressure and/or            temperature sensors, to guide therapeutic intervention such            as optimization of peritoneal filling with peritoneal            hypothermia or resuscitation

What is claimed is:
 1. An apparatus for accessing a body space within abody, comprising: an elongate device configured for insertion into thebody; one or more sensors positioned on the elongate device such thatthe sensors define a plane which is perpendicular relative to an axisdefined by the elongate device, wherein the one or more sensors arepositioned to contact tissue adjacent to the elongate device duringadvancement into the body; a controller in communication with the one ormore sensors, wherein the controller is configured to receive one ormore signals from the tissue in contact with the one or more sensors anddetect a change in a property of the tissue as the elongate device isadvanced, and wherein the controller is further configured to determinea position of the elongate device relative to the body space based uponthe change detected in the property as the elongate device is advanced.2. A method for accessing a body space within a body, comprising:advancing an elongate device into the body while contacting tissueadjacent to the elongate device during advancement via one or moresensors positioned on the elongate device, wherein the one or moresensors define a plane which is perpendicular relative to an axisdefined by the elongate device; receiving one or more signals from thetissue in contact with the one or more sensors; detecting a change in aproperty of the tissue via a controller in communication with the one ormore sensors as the elongate device is advanced; and determining via thecontroller a position of the elongate device relative to the body spacebased upon the change detected in the property as the elongate device isadvanced.